The bits that conventional computers use are implemented by transistors that can either be on (1) or off (0). Qubits, in contrast, can be both on and off at the same time, which implies that they could be used to carry out two or more calculations simultaneously. In principle, therefore, quantum computers should run much faster than conventional, silicon-based ones, at least in calculations where parallel processing is helpful.And it's a little more than just 'in principle', it's happening;
...a Canadian company called D-Wave — whose backers include Amazon boss Jeff Bezos and the “investment arm” of the CIA (I am not making this up) — was quietly getting on with building and marketing a quantum computer. In 2011, D-Wave sold its first machine — a 128-qubit computer — to military contractor Lockheed Martin. And last week it was announced that D-Wave had sold a more powerful machine to a consortium led by Google and NASA and a number of leading universities in the United States.We're sure Paul David is suitably appalled that a government agency hasn't stepped in to put a halt to these impatient entrepreneurs who might put us on the wrong path.